In the past few years, the rate of smart device adoption is accelerating. According to Gartner in their report dated May 19, 2011, worldwide smart device sales to end users totaled over 100 million units in the first quarter of 2011, an increase of 85 percent year-to-year. The availability of digital application distribution platforms was a big contribution to this growth. Many end users purchase smart devices for the purpose of using business applications, educational applications, games, and other applications available on the smart devices. As of Jun. 6, 2011, there are at least 425,000 third-party applications officially available on the App Store®.
Many smart devices use a multi-touch interface, which has a touch screen for direct finger input as its main means for interaction instead of having a keyboard and/or a keypad. Common resolutions for smart device screens vary from 240×320 to 768×1024, with many flagship smart devices at 768×1024. As a result, the touch screen can be very sensitive to even accidental taps on the screen.
One problem with some flagship smart devices, such as iPhone®, iPad®, Samsung Galaxy®, Samsung Galaxy Tab® etc., is that there is a physical home button near its touch screen or a home button on its touch screen. An accidental tap on the home button can terminate business applications, educational applications, games or applications that an end user is using. For example, a child using an educational application on a smart device may accidentally tap a home button, or tap the home button against the intentions of the parents. When that happens, the smart device's display automatically switches to a home screen, and the child may have difficulties in finding and going back to the educational application, contrary to the educational intention of the parents. As another example, multiple devices may be distributed to a group of students by a single educator with the intent of using a specific educational application. Many of the students may intentionally press the home button against the wishes of the educator. As a further example, devices may be distributed to a group of employees for a single specific business purpose, and the employees may use the home button to use the device for non-work related purposes.